Transcription
It's Medicos is perfection. Alice. Welcome to my channel, and today we will talk about leukemoid reaction. So let's get started. But first, what does leukemoid mean? So, leuco is leukemia, and oh, it means like it's a leukemia-like condition. It's like leukemia, but it's not leukemia. Leukemoid reaction is not cancer. Leukemoid reaction is a benign condition. It's an exaggerated leukocyte response against a microbial pathogen or in response to stress. Usually, white blood cell count will be greater than 50,000, but again, it's not leukemia. It could be either myeloid or lymphoid in origin.
What are the causes of leukemoid reaction? Many of them could be hemorrhage; could be like drugs such as dapsone, sulfa drugs, steroids; could be stress; it could be an infection such as tuberculosis, CF, pertussis, etc., etc. So the take-home message is leukemoid reaction is not leukemia, as we have discussed before in the previous video. We talked about alkaline phosphatase and the scoring method. When the white blood cells are doing their job and they're kind of mature, LAP score is high. If white blood cells are useless and less mature, LAP score is low. So leukemoid reaction will have high LAP score. CML will have low LAP score.
As you know, when you have a leukemoid reaction, keep calm; it's benign. Treat the underlying condition, if any. And the differential diagnosis is chronic myelogenous leukemia. This is very important. What do we do? We try to rule out chronic myelogenous leukemia by getting the bone marrow biopsy, by cytogenetics to find the Philadelphia chromosome. If none exist, let's just make sure that the LAP score is high. And if the LAP score is high and the bone marrow biopsy doesn't have CML, cytogenetics doesn't have that Philadelphia chromosome, then we confirm it's leukemoid reaction.
And let's try to answer the case of the previous video: 63-year-old female, notably high neutrophil count for a long time. This is chronic neutrophilia, presents with splenomegaly. Okay, bone marrow biopsy with cytogenetics presents 9;22 translocation. This is the Philadelphia chromosome. This is splenomegaly; neutrophilia; together we have CML, and the aged pattern fits perfectly. Which of the following findings are expected on lab investigation? TAR-positive is wrong; this is hairy cell leukemia. Blasts greater than 50 percent of the bone marrow: this is very rare, but this is an acute leukemia, not a chronic one, and usually it's not like 50 percent; it's kind of more than 20. Auer rods is AML; it's an acute leukemia. We're talking about CML. Low LAP score is, of course, the correct answer, and this is different from leukemoid reaction because leukemoid reaction have what? Have high LAP score.
And we are done for the day. Please consider subscribing to my YouTube channel. Follow me on Facebook, SoundCloud. Please consider supporting my work on patreon.com to get early access to my videos, plus other notes and stuff like that. I'll see you then. Be safe, stay happy, and study hard. It's Medicos is perfection. Alice.